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Playlist Fractions and Decimals 14 videos

1
Pre-Algebra: Adding and Subtracting Fractions and Decimals
6156 Views

Worried about adding and subtracting fractions? Never fear. It's so easy that it will only take up a fraction of your time: just use multiplication...

2
Converting Decimals
1956 Views

This video explains how to convert between decimals, percents, and fractions. All three of these languages are just different ways of showing parts...

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Decimals in the Real World 647 Views


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Transcript

00:00

Thank you We sneak in and here's your shmoop du

00:05

jour brought to you by electricity Say what Kristoff paise

00:13

fifteen cents per kilowatt hour for electricity which means that

00:16

he paid fifteen cents per hour to run an appliance

00:18

rated at one kilowatt His air conditioner is on constantly

00:22

which cost him five dollars and forty cents a day

00:25

Her stuff also has an electric oven I'm using his

00:29

oven for an hour and a half cost forty five

00:32

cents Chris stops oven is rated at blank kilowatts more

00:36

than his air conditioner Yeah All right Well is there

00:40

anything less fun than dealing with utility bills Don't say

00:43

taking the g e d all right so poor christoph

00:46

is getting slapped around by the power company What else

00:49

is we've all been there Fifteen cents per kilowatt hour

00:52

for electric which were told means that he pays fifteen

00:55

cents to run a one kilowatt appliance for one hour

00:58

Well running the a c cost him five dollars and

01:01

forty cents each day and using the oven cost in

01:04

forty five cents each hour and a half And we

01:07

need to know how the oven is rated compared to

01:10

the e a c Okay well let's roll up our

01:12

sleeves and be prepared to get dirty if we call

01:15

p the power rating of an appliance and see the

01:17

cost of running it for each hours than the product

01:20

P age would be the kilowatt hours used by running

01:23

an appliance rated at p for eight hours Here we've

01:27

got all that very clever people Each kilowatt hour cost

01:32

fifteen cents so we multiply ph by point one five

01:35

to get our cost or see so c equals point

01:39

one Five p h well to compare the ratings of

01:42

christoph to appliances will first need to find the rating

01:45

of the a c that's p a c and the

01:48

rating of the oven he oh separately for the a

01:52

c we're told that five dollars and forty cents or

01:54

five point four equals point one five times p a

01:57

c times twenty four number of hours in a day

02:01

So by dividing to get the rating by itself we

02:04

get p a c equals five point four divided by

02:08

point one five times twenty four for a total of

02:10

one point five kilowatts Then we could do the same

02:13

deal for the oven Point four Five equals point one

02:18

five times p o times one point five the number

02:23

of hours per stop is using it Well this gives

02:26

us a point Four five divided by point one five

02:28

times one point five for a total of two kilowatts

02:31

Phil comparing apples to apples this case kilowatt kilowatts looks

02:36

like the oven is rated at two minus one point

02:39

five floor point Five kilowatts More than the a c

02:44

and that's Our final answer Hopefully this problem helped catch 00:02:47.392 --> [endTime] you up on current events